/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.support;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;

/**
 * Extension to the standard {@link BeanFactoryPostProcessor} SPI, allowing for
 * the registration of further bean definitions <i>before</i> regular
 * BeanFactoryPostProcessor detection kicks in. In particular,
 * BeanDefinitionRegistryPostProcessor may register further bean definitions
 * which in turn define BeanFactoryPostProcessor instances.
 *
 * @author Juergen Hoeller
 * @since 3.0.1
 * @see org.springframework.context.annotation.ConfigurationClassPostProcessor
 */
// 标准的BeanFactoryPostprocessor SPI扩展
// 允许在普通的BeanFactoryPostProcessor检测之前注册更多的BeanDefinition
// 特别的是，BeanDefinitionRegistryPostProcessor可以注册BeanFactoryPostProcessor
public interface BeanDefinitionRegistryPostProcessor extends BeanFactoryPostProcessor {

	/**
	 * Modify the application context's internal bean definition registry after its
	 * standard initialization. All regular bean definitions will have been loaded,
	 * but no beans will have been instantiated yet. This allows for adding further
	 * bean definitions before the next post-processing phase kicks in.
	 * @param registry the bean definition registry used by the application context
	 * @throws org.springframework.beans.BeansException in case of errors
	 */

	// 可以对在应用上下文中的内部BeanDeinitionRegistry实例化之后进行修改。
	// 特别强调!!
	// 此时，BeanDefinitionRegistry中所有的普通BeanDefinition都已经加载了，但是未实例化。
	// 这个方法允许在后处理阶段之前向BeanDefinitionRegistry添加BeanDefinition。
	// (也可以增强，删除和修改Bean定义)
	// 注意:此时，与BeanFactoryPostProcessor一样，此时只是Bean定义，不要在此时
	// 真正的对Bean进行实例化，否则会导致Bean过早实例化导致难以预期的问题。
	void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException;

}
